But freaked-out snorkelers can relax. The behavior, scientists say, is just one example of how manatees use their uniquely developed sense of touch.

New research suggests that manatees' tactile sense is so finely tuned that the animals may experience "touch at a distance"—an ability to "feel" objects and events in the water from relatively far away.

In recent studies marine biologists Roger Reep and Diana Sarko at the University of Florida in Gainesville found that the giant mammals are covered with special whiskerlike hairs that act as sensors.

"We discovered that [manatees] have what are called tactile hairs all over their bodies, unlike most mammals, which just have whiskers on their faces," said Reep, from the university's College of Veterinary Medicine.

Together these tactile hairs form a kind of sensory array, the biologists say, possibly allowing manatees to detect changes in current, water temperature, and even tidal forces.

As for a manatee puckering up for a diver, Sarko explained, that's just the animal's way of collecting information by spreading out the hairs around its mouth to sense what it's approaching.

"Those facial hairs are actively exploring the environment around them," she said.

"But it might have liked you. I can't be sure."

Migrating in a Maze

Sarko and Reep's discovery could explain how manatees perform complex tasks, such as making long and convoluted migrations in murky water, despite having poor eyesight.